Solid titanium catalyst component, olefin polymerization catalyst, and process for producing olefin polymer

ABSTRACT

The present invention provides a process for producing an α-olefin polymer comprising polymerizing or copolymerizing (a) C 3  or higher α-olefin (s) in the presence of an olefin polymerization catalyst comprising solid titanium catalyst component (I) containing titanium, magnesium, halogen, and a compound with a specific structure having two or more ether linkages and organometallic catalyst component (II) with high catalytic activity. In this process, particularly even in (co)polymerizing (a) higher olefin(s), demineralization is unnecessary. A 4-methyl-1-pentene-based polymer obtained by polymerization using the catalyst of the present invention is excellent in tacticity, transparency, heat resistance, and releasability, and the polymer is particularly suitable for a release film.

This application is a Divisional application of U.S. application Ser.No. 12/851,919, having a filing date of Aug. 6, 2010, which in turn is aDivisional application of U.S. application Ser. No. 11/667,680 having afiling date of May 14, 2007, which is a National Stage of PCTInternational Application No. PCT/JP2005/021059 filed on Nov. 16, 2005,which claims priority from Japanese Patent Application No. 2004-332672filed on Nov. 17, 2004, the entire disclosure of each of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an olefin polymerization catalyst, aprocess for producing an α-olefin polymer, and a film obtained from theα-olefin polymer. Specifically, the present invention relates to acatalyst used for polymerizing or copolymerizing (a) C₃ or higherα-olefin(s), a process for producing the α-olefin polymer, and a filmsuitable as a release film.

BACKGROUND ART

As a catalyst used for producing olefin polymers such as homopolymers orcopolymers of ethylene and/or α-olefins, catalysts containing a titaniumcompound loaded on activated magnesium halide have been known so far. Assuch olefin polymerization catalysts (hereinafter, “polymerizationcatalysts” may include copolymerization catalysts), there are knowncatalysts containing a solid titanium catalyst component composed ofmagnesium, titanium, halogen, and an electron donor and anorganoaluminum compound.

These catalysts have high catalytic activity for polymerization of C₃ orhigher α-olefins such as propylene and 1-butene and copolymerization oftwo or more monomers selected from such α-olefins, similarly to the caseof ethylene polymerization. Further, the resulting copolymers have highmelting points because of high tacticity and crystallinity. It is knownthat, among these catalysts, a catalyst containing a solid titaniumcatalyst component loading an electron donor selected from carboxylatesincluding phthalates as typical examples, an alkylaluminum, and asilicon compound having at least one Si—OR (wherein R is a hydrocarbongroup) serving as cocatalysts exhibits particularly excellentperformances (for example, Japanese Patent Laid-Open Publication No.S57-63310, Japanese Patent Laid-Open Publication No. S58-83006, etc.).

It is also disclosed that a catalyst containing a solid titaniumcatalyst component containing a compound with two or more ether linkagesas an electron donor has high polymerization activity (for example,Japanese Patent Laid-Open Publication No. H3-706, Japanese Patent No.3476793, Japanese Patent Laid-Open Publication No. H4-218508, JapanesePatent Laid-Open Publication No. 2003-105022, etc.).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The present invention was conducted in view of the above background art,having an object to provide a solid titanium catalyst componentexhibiting high catalytic activity and stereospecificity forpolymerization or copolymerization of monomers including (a) C₃ orhigher α-olefin(s), an olefin polymerization catalyst, and a process forproducing an olefin polymer. Another object of the present invention isto provide an α-olefin polymer that is obtained using the olefinpolymerization catalyst and is excellent in tacticity, crystallinity,and transparency.

Means for Solving the Problems

The present inventors have intensively studied to solve the aboveproblems and found that a catalyst formed from a solid titanium catalystcomponent containing a specific compound with a specific structurehaving two or more ether linkages as an electron donor and a specificorganometallic catalyst component exhibits high catalytic activity andstereospecificity for polymerization or copolymerization of monomersincluding (a) C₃ or higher α-olefin(s), and that the specific α-olefincopolymer obtained using this catalyst satisfies a specific relationbetween the composition of the copolymer and the composition of itsdecane-soluble component, and that this copolymer is excellent intransparency and releasability when used for films. The presentinvention has been accomplished based on these findings.

Namely, the present invention provides a solid titanium catalystcomponent (I) containing titanium, magnesium, halogen, and a compoundhaving two or more ether linkages interposed with plural atomsrepresented by general formula (1) below.

(In the formula, R¹, R³, R⁶, and R⁸ are hydrogen atoms; R² is a methylgroup; R⁷ is a methyl group or hydrogen atom; each of R⁴ and R⁵ is anatom or group having at least one kind of element selected from carbon,hydrogen, oxygen, halogens, nitrogen, sulfur, phosphorus, boron, andsilicon; and the total number of carbon atoms in R⁴ and R⁵ is 4 to 6.)

The present invention also provides an olefin polymerization catalystcontaining the solid titanium catalyst component (I) and anorganometallic catalyst component (II) containing a metal selected fromthe metals in Groups I to III.

The present invention also provides a process for producing an α-olefinpolymer comprising polymerizing or copolymerizing (a) C₃ or higherα-olefin(s) in the presence of the above olefin polymerization catalyst.

The present invention also provides

a 4-methyl-1-pentene copolymer that is a copolymer containing 80 to 99.9mass % of structural units derived from 4-methyl-1-pentene and 0.1 to 20mass % of structural units derived from at least one C₃₋₁₁ α-olefinexcept 4-methyl-1-pentene, wherein the ratio of the content ofstructural units derived from the C₃₋₁₁ α-olefin (s) except4-methyl-1-pentene in the n-decane-soluble component of said copolymer,a₁ in mass %, to the content of structural units derived from the C₃₋₁₁α-olefin(s) except 4-methyl-1-pentene in said copolymer, b₁ in mass %,(a₁/b₁) is in the range of 2.0 to 4.0; and

a 4-methyl-1-pentene copolymer that is a copolymer containing 80 to 99.9mass % of structural units derived from 4-methyl-1-pentene and 0.1 to 20mass % of structural units derived from at least one C₁₂₋₂₀ α-olefin,wherein the ratio of the content of structural units derived from theC₁₂₋₂₀ α-olefin(s) in the n-decane soluble component of said copolymer,a₂ in mass %, to the content of structural units derived from the C₁₂₋₂₀α-olefin(s) in said copolymer, b₂ in mass %, (a₂/b₂) is in the range of3.0 to 6.0.

The present invention also provides a film comprising the above4-methyl-1-pentene copolymer.

The present invention also provides

a film obtained by forming a copolymer containing 80 to 99.9 mass % ofstructural units derived from 4-methyl-1-pentene and 0.1 to 20 mass % ofstructural units derived from at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene, wherein the ratio of the blocking factor of saidfilm, c₁ in g/cm, to the content of structural units derived from theC₃₋₁₁ α-olefin(s) except 4-methyl-1-pentene in the n-decane-solublecomponent of said copolymer, d₁ in mol %, (c₁/d₁) is in the range of 0.1to 1.5; and

a film obtained by forming a copolymer containing 80 to 99.9 mass % ofstructural units derived from 4-methyl-1-pentene and 0.1 to 20 mass % ofstructural units derived from at least one C₁₂₋₂₀ α-olefin, wherein theratio of the blocking factor of said film, c₂ in g/cm, to the content ofstructural units derived from the C₁₂₋₂₀ α-olefin(s) in then-decane-soluble component of said copolymer, d₂ in mol %, (c₂/d₂) is inthe range of 0.1 to 1.5.

The present invention also provides a release film comprising the above4-methyl-1-pentene copolymer.

Effects of the Invention

The process for producing an α-olefin polymer according to the presentinvention is characterized in that (a) C₃ or higher α-olefin(s) is/arepolymerized or copolymerized in the presence of an olefin polymerizationcatalyst comprising a solid titanium catalyst component (I) containingtitanium, magnesium, halogen, and a compound having two or more etherlinkages interposed with plural atoms represented by general formula (1)and an organometallic catalyst component (II) containing a metalselected from the metals in Groups I to III. The process for producingan α-olefin polymer according to the present invention can produce anα-olefin polymer having excellent tacticity, crystallinity, andtransparency in high catalytic efficiency.

A film with excellent releasability can be also provided from the resinproduced as above. Further, since the catalyst has a polymerizationactivity higher than that of conventional catalysts, demineralizationstep is unnecessary, and thereby the production cost of resins can begreatly reduced.

BEST MODE FOR CARRYING OUT THE INVENTION

The olefin polymerization catalyst and the process for producing anolefin polymer (polymer or copolymer) according to the present inventionare specifically described below.

[Solid Titanium Catalyst Component (I)]

Solid titanium catalyst component (I) contained in the olefinpolymerization catalyst of the present invention is generally preparedby contacting a magnesium compound and a titanium compound with acompound having two or more ether linkages represented by generalformula (1).

<Magnesium Compound>

A magnesium compound may be used for preparing solid titanium catalystcomponent (1). The magnesium compound includes magnesium compoundshaving reducing ability and magnesium compounds having no reducingability.

The magnesium compound having reducing ability includes, for example,organomagnesium compounds represented by general formula (2) below.X_(n)MgR⁹ _(2-n)  (2)(In the formula, 0≦n<2; R⁹ is a hydrogen atom or a C₁₋₂₀ alkyl, aryl, orcycloalkyl group; two R⁹s may be identical or different when n is 0; andX is a halogen atom.)

Such organomagnesium compounds having reducing ability include,specifically, dimethylmagnesium, diethylmagnesium, dipropylmagnesium,dibutylmagnesium, diamylmagnesium, dihexylmagnesium, didecylmagnesium,ethylmagnesium chloride, propylmagnesium chloride, butylmagnesiumchloride, hexylmagnesium chloride, amylmagnesium chloride,butylethoxymagnesium, ethylbutylmagnesium, octylbutylmagnesium,butylmagnesium hydride, and the like. These magnesium compounds may beused alone or may form a complex with an organoaluminum compounddescribed later. These magnesium compounds may be liquid or solid.

Specific examples of the magnesium compound having no reducing abilityinclude magnesium halides such as magnesium chloride, magnesium bromide,magnesium iodide, and magnesium fluoride; alkoxymagnesium halides suchas methoxymagnesium chloride, ethoxymagnesium chloride,isopropoxymagnesium chloride, butoxymagnesium chloride, andoctyloxymagnesium chloride; aryloxymagnesium halides such asphenoxymagnesium chloride and methylphenoxymagnesium chloride;alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium,butoxymagnesium, n-octyloxymagnesium, and 2-ethylhexyloxymagnesium;aryloxymagnesiums such as phenoxymagnesium and dimethylphenoxymagnesium;magnesium carboxylates such as magnesium laurate and magnesium stearate;and the like.

The magnesium compound having no reducing ability may be a compoundderived from the above-described magnesium compound having reducingability or a compound generated in preparing the catalyst component. Themagnesium compound having no reducing ability can be generated from themagnesium compound having reducing ability, for example, by contactingthe magnesium compound having reducing ability with a polysiloxane,halogen-containing compound, or compound having an OH group or labilecarbon-oxygen bond such as halogen-containing silane, halogen-containingaluminum compound, ester, and alcohol.

Besides the magnesium compounds having reducing ability and magnesiumcompounds having no reducing ability, the magnesium compound may be acomplex compound or double compound formed from the magnesium compoundand another metal, or a mixture of the magnesium compound and anothermetal compound. Two or more of the magnesium compounds may be used incombination, and they may be used in either liquid or solid state. Whenthe magnesium compound is solid, it may be liquefied with an alcohol,carboxylic acid, aldehyde, amine, metal acid ester, or the like.

Of these, preferably used are magnesium compounds having no reducingability, especially halogen-containing magnesium compounds. Of thehalogen-containing magnesium compounds, further preferred are magnesiumchloride, alkoxymagnesium chlorides, and aryloxymagnesium chlorides.

<Titanium Compound>

As the titanium compound used in preparing solid titanium catalystcomponent (I) contained in the catalyst used in the process forproducing the α-olefin polymer according to the present invention,desirable are liquid titanium compounds, which include, for example,tetravalent titanium compounds represented by the following generalformula.Ti(OR¹⁰)_(g)X_(4-g)  (3)(R¹⁰ is a hydrocarbon group; X is a halogen atom; and 0≦g≦4.)

More specifically, the titanium compound includes titanium tetrahalidessuch as TiCl₄, TiBr₄, and TiI₄; alkoxytitanium trihalides such asTi(OCH₃)Cl₃, Ti(OC₂H₅)Cl₃, Ti(O-n-C₄H₉)Cl₃, Ti(OC₂H₅)Br₃, andTi(OCH₂C(CH₃)₂)Br₃; alkoxytitanium dihalides such as Ti(OCH₃)₂Cl₂,Ti(OC₂H₅)₂Cl₂, Ti(O-n-C₄H₉)₂Cl₂, and Ti(OC₂H₅)₂Br₂; alkoxytitaniummonohalides such as Ti(OCH₃)₃Cl, Ti(OC₂H₅)₃Cl, Ti(O-n-C₄H₉)₃Cl, andTi(OC₂H₅)₃Br; and tetraalkoxytitaniums such as Ti(OCH₃)₄, Ti(OC₂H₅)₄,Ti(O-n-C₄H₉)₄, Ti(OCH₂C(CH₃)₂)₄, tetra(2-ethylhexyloxy)titanium, andtetra(2-ethylhexyloxy)titanium.

Among these, titanium tetrahalides are preferred, and titaniumtetrachloride is particularly preferred. These titanium compounds may beused singly or as a mixture thereof and may be diluted with ahydrocarbon or halogenated hydrocarbon for use.

<Compound Represented by General Formula (1)>

In preparing solid titanium catalyst component (I) contained in thecatalyst used in the present invention, besides the above compounds,there is used a compound having two or more ether linkages interposedwith plural atoms represented by general formula (1).

The compound having two or more ether linkages used in preparing solidtitanium catalyst component (I) is represented by general formula (1)below.

(In the formula, R¹, R³, R⁶, and R⁸ are hydrogen atoms; R² is a methylgroup; R⁷ is a methyl group or hydrogen atom; each of R⁴ and R⁵ is anatom or group having at least one kind of element selected from carbon,hydrogen, oxygen, halogens, nitrogen, sulfur, phosphorus, boron, andsilicon; and the total number of carbon atoms in R⁴ and R⁵ is 4 to 6.)

As the compound having two or more ether linkages, preferred arecompounds in which R⁴ and R⁵ in general formula (1) are C₁₋₄ hydrocarbongroups and the total number of carbon atoms in R⁴ and R⁵ is 4 to 6. Morepreferred are compounds in which R⁴ and R⁵ in general formula (1) areC₁₋₄ hydrocarbon groups and the total number of carbon atoms in R⁴ andR⁵ is 4 to 5. As the C₁₋₄ hydrocarbon group, preferred are methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl.Particularly preferred are methyl, ethyl, n-propyl, and n-butyl.

Such compounds having two or more ether linkages include, specifically,2-methyl-2-n-propyldiethoxypropane, 2-methyl-2-isopropyldiethoxypropane,2-methyl-n-butyldiethoxypropane, 2,2-diethyl-1,3-diethoxypropane,2-ethyl-2-n-propyldiethoxypropane, 2-ethyl-2-isopropyldiethoxypropane,2,2-di-n-propyldiethoxypropane, and the like. Particularly preferred are2-methyl-2-n-propyl-1,3-diethoxypropane and2,2-diethyl-1,3-diethoxypropane.

<Other Components>

Solid titanium catalyst component (I) used in preparing thepolymerization catalyst may be prepared by using, besides the abovecomponents, other components conventionally used for solid titaniumcatalyst components, as long as the objective of the present inventionis not impaired. Such components include, for example, catalyst supportsand reaction auxiliaries such as organic and inorganic compoundscontaining silicon, phosphorus, aluminum, electron donor (III) describedlater, and the like.

As the catalyst support used are Al₂O₃, SiO₂, B₂O₃, MgO, CaO, TiO₂, ZnO,ZnO₂, SnO₂, BaO, ThO, resins such as styrene/divinylbenzene copolymer,and the like. Among these, preferred are Al₂O₃, SiO₂, andstyrene/divinylbenzene copolymer. The ether represented by generalformula (1) or electron donor (III) is not necessarily supplied asstarting materials. They may be generated during preparation of solidtitanium catalyst component (I).

Examples of electron donor (III) include organic acid esters, organicacid halides, organic acid anhydrides, ethers, ketones, tertiary amines,phosphite esters, phosphate esters, phosphoramides, carboxamides,nitriles, and the like. Specifically, there may be mentioned, C₃₋₁₅ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone,acetophenone, benzophenone, cyclohexanone, and benzoquinone; C₂₋₁₅aldehydes such as acetaldehyde, propionaldehyde, octylaldehyde,benzaldehyde, tolualdehyde, and naphthaldehyde; C₂₋₁₈ organic acidesters such as methyl formate, methyl acetate, ethyl acetate, vinylacetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethylpropionate, methyl lactate, ethyl valerate, methyl chloroacetate, ethyldichloroacetate, methyl methacrylate, ethyl crotonate, ethylcyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propylbenzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenylbenzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate,ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethylethoxybenzoate, γ-butyrolactone, δ-valerolactone, coumalin, phthalide,and ethylene carbonate; C₂₋₁₅ acid halides such as acetyl chloride,benzoyl chloride, toluoyl chloride, and anisyl chloride; C₂₋₂₀ etherssuch as methyl ether, ethyl ether, isopropyl ether, butyl ether, amylether, tetrahydrofuran, anisole, and diphenyl ether; acid amides such asN,N-dimethylacetamide, N,N-diethylbenzamide, and N,N-dimethyltoluamide;tertiary amines such as trimethylamine, triethylamine, tributylamine,tribenzylamine, and tetramethylethylenediamine; and nitriles such asacetonitrile, benzonitrile, and tolunitrile. Among these, aromaticcarboxylates are preferred. Two or more of these compounds may be usedin combination. The organic acid esters also include polycarboxylicesters as particularly preferred examples.

<Method for Preparing Solid Titanium Catalyst Component (I)>

Solid titanium catalyst component (I) contained in the polymerizationcatalyst used in the process according to the present invention isprepared, for example, by contacting the above magnesium compound,liquid titanium compound, and compound having two or more etherlinkages, and optionally, the catalyst support, electron donor (III),and the like. There is no particular limitation on the method forpreparing solid titanium catalyst component (I) using these compounds.Brief explanation will be given with several examples below.

1) A method of contacting a magnesium compound, a compound having two ormore ether linkages represented by general formula (1), and a titaniumcompound in any order to react. In this reaction, each component may bepre-treated with the compound having two or more ether linkages and/orelectron donor (I) or a reaction auxiliary such as organoaluminumcompound and halogen-containing silicon compound.2) A method of reacting a liquid magnesium compound having no reducingability and a liquid titanium compound in the presence of a compoundhaving two or more ether linkages represented by general formula (1) toprecipitate a solid magnesium-titanium complex.3) A method of further reacting the reaction product obtained in Method2) with a titanium compound.4) A method of further reacting the reaction product obtained inMethod 1) or 2) with an ether represented by general formula (1) and atitanium compound.5) A method of pulvelizing a magnesium compound, a compound having twoor more ether linkages represented by general formula (1), and atitanium compound to form solid, which is then treated with halogen, ahalogen-containing compound, or an aromatic hydrocarbon.

This method may include a step of pulverizing only the magnesiumcompound, a step of pulverizing the magnesium compound and compoundhaving two or more ether linkages represented by general formula (1), ora step of pulverizing the magnesium compound and titanium compound.These compounds may be pulverized in the presence of a pulverizationauxiliary or the like. Further, the pulverization may be followed bypre-treatment with a reaction auxiliary before the treatment withhalogen or the like. The reaction auxiliary includes organoaluminumcompounds, halogen-containing silicon compounds, and the like.

6) A method of treating the product obtained in Methods 1) to 4) withhalogen, a halogen-containing compound, or an aromatic hydrocarbon.

7) A method of contacting a catalyst support such as metal oxide,organomagnesium compound, and halogen-containing compound followed bycontacting the product with a compound having two or more ether linkagesrepresented by general formula (1) and a titanium compound.8) A method of contacting a magnesium compound such as organic acidmagnesium salt, alkoxymagnesium, and aryloxymagnesium with a compoundhaving two or more ether linkages represented by general formula (1), atitanium compound, and optionally a halogen-containing compound.9) A method of reacting a solution containing at least a magnesiumcompound and an alkoxytitanium with a titanium compound, a compoundhaving two or more ether linkages represented by general formula (1),and optionally a halogen-containing compound such as halogen-containingsilicon compound.10) A method of reacting a liquid magnesium compound having no reducingability and an organoaluminum compound to precipitate a solidmagnesium-aluminum complex, which is then reacted with a compound havingtwo or more ether linkages represented by general formula (1) and atitanium compound.

Solid titanium catalyst component (I) containing the compoundrepresented by general formula (1) is obtained by such methods.

In preparing solid titanium catalyst component (I) by such methods, forthe magnesium compound, the liquid titanium compound, and the compoundhaving two or more ether linkages represented by general formula (1),their amounts to be used depend on the compounds, the conditions forcontact, the order of contact, and the like. The amount, used per moleof magnesium atoms, of the compound having two or more ether linkagesrepresented by general formula (1) is preferably 0.01 moles to 5 moles,and particularly preferably 0.05 moles to 1 mole, while that of theliquid titanium compound is preferably 0.1 moles to 1000 moles, andparticularly preferably 1 mole to 200 moles.

The temperature in contact is generally −70° C. to 200° C., andpreferably 10° C. to 150° C. Solid titanium catalyst component (I) thusobtained contains titanium, magnesium, halogen, and the ether having twoor more ether linkages represented by general formula (1).

In solid titanium catalyst component (I), the content of the compoundhaving two or more ether linkages represented by general formula (1) ispreferably 1 to 40 mass %, and more preferably 3 to 20 mass %, while thetitanium content is preferably 0.4 to 15 mass %, and more preferably 1to 7 mass %.

The atomic ratio of halogen/titanium is preferably 2 to 100, and morepreferably 4 to 90. The molar ratio of the compound having two or moreether linkages/titanium is preferably 0.01 to 100, and more preferably0.2 to 10. The atomic ratio of magnesium/titanium is preferably 2 to100, and more preferably 4 to 50.

<Olefin Polymerization Catalyst>

The olefin polymerization catalyst of the present invention containssolid titanium catalyst component (I) and organometallic catalystcomponent (II) containing a metal element selected from the metals inGroups I to III.

<Organometallic Catalyst Component (II)>

As organometallic catalyst component (II) contained in the olefinpolymerization catalyst of the present invention, there may be used, forexample, organoaluminum compound, complex alkylated derivatives of aGroup-I metal and aluminum, organometallic compounds of a Group-IImetal, and the like.

Examples of organometallic catalyst component (II) include, for example,organoaluminum compounds represented by general formula (4) below.Ra_(n)AlX_(3-n)  (4)(In the formula, Ra is a C₁₋₁₂ hydrocarbon group; X is a halogen orhydrogen atom; and 1≦n≦3.)

In general formula (4), Ra is a C₁₋₁₂ hydrocarbon group, for example, analkyl, cycloalkyl, or aryl group. Specifically, it includes methyl,ethyl, n-propyl, isopropyl, isobutyl, pentyl, hexyl, octyl, cyclopentyl,cyclohexyl, phenyl, tolyl, and the like. Among these, preferred aretrialkylaluminums (n=3), particularly, triethylaluminum,triisobutylaluminum, and the like. These compound may be used incombination of two or more.

(Electron Donor (IV))

The olefin polymerization catalyst of the present invention may containan electron donor as needed, besides solid titanium catalyst component(I) and organometallic catalyst component (II). As the electron donor,electron donor (III) above and other known electron donors used inolefin polymerization catalysts may be used without limitation. Amongthem, preferred examples are electron donor (IV), electron donor (V),and electron donor (VI) below.

Electron donor (IV) used here includes organosilicon compoundsrepresented by general formula (2) below.R¹¹ _(n)Si(OR¹²)_(4-n)  (2)(In the formula, 0<n<4; each of R¹¹ and R¹² represents a hydrocarbongroup; n R¹¹s may be identical or different; and (4−n) OR¹²s may beidentical or different.)

The organosilicon compound represented by the above general formulaincludes, specifically, trimethylmethoxysilane, trimethylethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,diisopropyldimethoxysilane, t-butylmethyldimethoxysilane,t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane,diphenyldimethoxysilane, phenylmethyldimethoxysilane,diphenyldiethoxysilane, bis-o-tolyldimethoxysilane,bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane,bis-p-tolyldiethoxysilane, bis(ethylphenyl)dimethoxysilane,dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane,cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane,n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane,phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane,methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane,t-butyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane,phenyltriethoxysilane, γ-aminopropyltriethoxysilane,chlorotriethoxysilane, ethyltri(isopropoxy)silane, vinyltributoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,2-norbornyltrimethoxysilane, 2-norbornyltriethoxysilane,2-norbornylmethyldimethoxysilane, ethyl silicate, butyl silicate,trimethylphenoxysilane, methyltriallyloxysilane,vinyltris(β-methoxyethoxy)silane, vinyltriacetoxysilane,dimethyltetraethoxydisiloxane, cyclopentyltrimethoxysilane,2-methylcyclopentyltrimethoxysilane,2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,dicyclopentyldimethoxysilane, bis(2-methylcyclopentyl)dimethoxysilane,bis(2,3-dimethylcyclopentyl)dimethoxysilane,dicyclopentyldiethoxysilane, tricyclopentylmethoxysilane,tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane,hexenyltrimethoxysilane, dicyclopentylethylmethoxysilane,dicyclopentylmethylethoxysilane, cyclopentyldimethylmethoxysilane,cyclopentyldiethylmethoxysilane, cyclopentyldimethylethoxysilane, andthe like. Other organosilicon compounds used for olefin polymerizationcatalysts described in literatures may be also used without limitation.

Of these, preferably used are trimethylmetohxysilane,ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane,vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane,diphenyldimethoxysilane, phenylmethyldimethoxysilane,bis-p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane,dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane,2-norbornyltriethoxysilane, 2-norbornylmethyldimethoxysilane,phenyltriethoxysilane, dicyclopentyldimethoxysilane,hexenyltrimethoxysilane, cyclopentyltriethoxysilane,tricyclopentylmethoxysilane, and cyclopentyldimethylmethoxysilane.Particularly preferred are trimethylmethoxysilane,cyclohexylmethyldimethoxysilane, and dicyclopentyldimethoxysilane. Theseorganosilicon compounds may be used in combination of two or more.

Electron donor (V) includes compounds having two or more ether linkagesinterposed with plural atoms represented by general formula (3) below.It is needless to say that the compounds represented by general formula(1) are included in the compounds represented by general formula (3).

(In the formula, each of R²¹ to R²³ and R²⁶ to R²⁸ is an atom or groupcontaining at least one kind of element selected from carbon, hydrogen,halogens, nitrogen, sulfur, phosphorus, boron and silicon; any groups inR²¹ to R²³ or any groups in R²⁶ to R²⁸ may bond together forming a ringother than benzene ring; and each of R²⁴ and R²⁵ is an atom or groupcontaining at least one kind of element selected from carbon, hydrogen,oxygen, halogens, nitrogen, sulfur, phosphorus, boron, and silicon.)Such compounds can be preferably used.

As the compound having two or more ether linkages represented by generalformula (3), preferred are compounds in which R²² and/or R²⁷ is/are (an)atom(s) or group(s) selected from hydrogen atom, methyl group, ethylgroup, propyl group, and butyl group. More preferred are compounds inwhich R²² and/or R²⁷ is/are (an) atom(s) or group(s) selected fromhydrogen atom and methyl group.

The total number of carbon atoms in R²⁴ and R²⁵ is preferably 3 to 7.Each of R²⁴ and R²⁵ is preferably a C₁₋₄ hydrocarbon group.

The C₁₋₄ hydrocarbon group is preferably methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, or tert-butyl, and particularly preferablymethyl, ethyl, n-propyl, or n-butyl.

The compound having two or more ether linkages represented by generalformula (3) includes, specifically,2-isopentyl-2-isopropyl-1,3-dimethoxypropane,2-ethyl-2-n-propyl-1,3-dimethoxypropane,2-ethyl-2-methyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane,2-isobutyl-2-isopropyl-1,3-dimethoxypropane,2-methyl-2-n-propyldiethoxypropane, 2-methyl-2-isopropyldiethoxypropane,2-methyl-n-butyldiethoxyproapne, 2,2-diethyl-1,3-diethoxypropane,2-ethyl-2-n-propyldiethoxypropane, 2-ethyl-2-isopropyldiethoxypropane,2,2-di-n-propyldiethoxypropane, and the like.

Particularly preferred are 2-isobutyl-2-isopropyl-1,3-dimethoxypropane,2-methyl-2-n-propyl-1,3-diethoxypropane, and2,2-diethyl-1,3-diethoxypropane.

Besides the above compounds, there may be used compounds having pluralether linkages used for olefin polymerization catalysts described inliteratures such as Japanese Patent Laid-Open Publication No. H3-706above, and the like.

The compounds having two or more ether linkages represented by generalformula (3) may be also used in combination of two or more.

<Electron Donor (VI)>

Electron donor (VI) includes nitrogen-containing compounds,oxygen-containing compound other than above, phosphorous-containingcompounds, and the like.

As the nitrogen-containing compound, specifically, compounds as shownbelow may be used: 2,6-substituted piperidines such as

2,5-substituted pyrrolidines such as

substituted methylenediamines such asN,N,N′,N′-tetramethylmethylenediamine andN,N,N′,N′-tetraethylmethylenediamine; substituted methylenediamines suchas 1,3-dibenzylimidazolidine and 1,3-dibenzyl-2-phenylimidazolidine; andthe like.

As the phosphorus-containing compound, there may be used specificallyphosphites such as triethyl phosphite, tri-n-propyl phosphite,tri-isopropyl phosphite, tri-n-butyl phosphite, tri-isobutyl phosphite,diethyl n-butyl phosphite, and diethyl phenyl phosphite, and the like.

As the oxygen-containing compound, compounds as shown below may be used:2,6-substituted tetrahydropyrans and 2,5-substituted tetrahydropyranssuch as

and the like. Electron donor (IV), electron donor (V), and electrondonor (VI) described above may be used in combination of two or more.Among these, electron donor (IV) and electron donor (V) are preferred.The compounds represented by general formula (3) are more preferred. Thecompounds represented by general formula (I) are particularly preferred.

The polymerization catalyst of the present invention may contain othercomponents effective to olefin polymerization, besides the abovecomponents.

[Prepolymerization]

The olefin polymerization catalyst according to the present inventionmay be a prepolymerized catalyst obtained by prepolymerizing a C₅ orhigher branched α-olefin. In the prepolymerized catalyst, the amount ofC₅ or higher branched α-olefin prepolymerized is preferably 0.1 to 200g, more preferably 0.3 to 100 g, and particularly preferably 1 to 50 g,per gram of solid titanium catalyst component (I).

In the prepolymerization, the catalyst may be used in a concentrationhigher than that in the main polymerization described later. In theprocess for producing an α-olefin polymer according to the presentinvention, the concentration of solid titanium catalyst component (I)desirable for the prepolymerization is generally 0.01 to 200 millimoles,preferably 0.1 to 50 millimoles, and particularly preferably 1 to 20millimoles in terms of titanium atom per liter of the liquid medium.

The amount of organometallic catalyst component (II) may be selectedsuch that the amount of the polymer formed is preferably 0.1 to 200 g,and more preferably 0.3 to 100 g per gram of solid titanium catalystcomponent (I). The desirable amount is generally 0.1 to 300 moles,preferably 0.5 to 100 moles, and particularly preferably 1 to 50 molesper mole of titanium atoms in solid titanium catalyst component (I).

In the process for producing an olefin polymer according to the presentinvention, an electron donor may be used if needed in theprepolymerization. As the electron donor, there may be used electrondonor (III) above and other known electron donors used for olefinpolymerization catalysts without limitation. Among these, preferred areelectron donor (IV), electron donor (V), and electron donor (VI). In theprocess for producing an α-olefin polymer according to the presentinvention, the amount of the electron donor used here is preferably 0.1to 50 moles, more preferably 0.5 to 30 moles, and further preferably 1to 10 moles per mole of titanium atoms in solid titanium catalystcomponent (I).

The prepolymerization may be performed under such mild conditions that,for example, an olefin and the above catalyst components are added to aninert hydrocarbon medium. The inert hydrocarbon medium used hereincludes, specifically, aliphatic hydrocarbons such as propane, butane,pentane, hexane, heptane, octane, decane, dodecane, and kerosene;alicyclic hydrocarbons such as cyclopentane, cyclohexane, andmethylcyclopentane; aromatic hydrocarbons such as benzene, toluene, andxylene; halogenated hydrocarbons such as ethylene chloride andchlorobenzene; mixtures thereof; and the like. Among these inerthydrocarbon media, particularly, aliphatic hydrocarbons are preferablyused. When such an inert hydrocarbon medium is used, it is desirable toperform the prepolymerization in batch. The prepolymerization may beperformed in a medium of the olefin itself.

As the olefin used for the prepolymerization, preferred are C₅ or higherbranched α-olefins, which include 3-methyl-1-butene, 3-methyl-1-pentene,4-methyl-1-pentene, and 4,4-dimethyl-1-pentene. Among these,3-methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene are usedparticularly preferably.

The olefin used for the prepolymerization may be different from oridentical with the olefin used for the main polymerization describedlater. In the prepolymerization, the desirable reaction temperature isgenerally from −20 to +100° C., preferably from −20 to +80° C., and morepreferably from 0 to +40° C. In the prepolymerization, a molecularweight modifier such as hydrogen may be used.

[Process for Producing Olefin Polymer]

The process for producing an olefin polymer according to the presentinvention comprises polymerization or copolymerization (mainpolymerization) of at least one kind of monomer including a C₃ or higherα-olefin in the presence of the above olefin polymerization catalyst,optionally preceded by prepolymerization.

The C₃ or higher α-olefin includes propylene, 1-butene, 1-pentene,1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, 4-methyl-1-pentene, 3-methyl-1-pentene, and the like.There is used preferably a C₄ or higher α-olefin, more preferably C₆ orhigher α-olefin, further preferably a C₆₋₁₀ α-olefin, and particularlypreferably, 4-methyl-1-pentene.

In the process for producing an olefin polymer of the present invention,polymerization of the above α-olefin, particularly 4-methyl-1-pentene,can be performed with higher catalytic activity, and an olefin polymerwith superior tacticity and crystallinity can be obtained compared toprocesses with a conventional catalyst.

In the present invention, two or more C₃ or higher α-olefins may becopolymerized, or at least one C₃ or higher α-olefin may becopolymerized with ethylene.

In particular, when 4-methyl-1-pentene is used as one of the α-olefins,it is preferably copolymerized with a linear olefin in terms of highmechanical strength of the resultant polymer. The linear olefinincludes, specifically, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, and 1-octadecene.

In the process for producing an olefin polymer (polymerization process)according to the present invention, (a) C₃ or higher α-olefin(s) may bealso copolymerized with another monomer, which includes aromatic vinylcompounds such as styrene and allylbenzene; alicyclic vinyl compoundssuch as vinyl cyclohexane, cyclo-olefins such as cyclopentene,cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, and2-methyl-1,4:5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene; andcompounds having a plurality of unsaturated bonds including conjugatedor nonconjugated dienes such as 6-methyl-1,6-octadiene,7-methyl-1,6-ocatadiene, 6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene,6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene,6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 6-methyl-1,6-decadiene,7-methyl-1,6-decadiene, 6-methyl-1,6-undecadiene, isoprene, andbutadiene.

In the present invention, the polymerization may be performed by any ofliquid-phase polymerization such as solution polymerization, suspensionpolymerization, and bulk polymerization, gas-phase polymerization, andother known polymerization methods. In liquid-phase polymerization, theinert hydrocarbon described in the section of prepolymerization may beused as a solvent, or there may be used an olefin that is liquid underthe polymerization condition, which serves as a solvent.

In the process for producing an α-olefin polymer (polymerizationprocess) according to the present invention, the preferred amount ofsolid titanium catalyst component (I) used therein is, for example, inliquid polymerization, generally 0.0001 to 0.5 millimoles, andpreferably 0.0005 to 0.1 millimoles in terms of titanium atom per literof the whole volume of liquid phase. The preferred amount oforganometallic compound catalyst component (II) used therein isgenerally 1 to 2000 moles, and preferably 5 to 500 moles in terms of themetal atom in the organometallic compound catalyst component per mole oftitanium atoms in solid titanium catalyst component (I) in thepolymerization system.

The preferred amount of electron donor (IV), electron donor (V), orelectron donor (VI) used therein is generally 0.1 to 1000 moles, andpreferably 1 to 500 moles per mole of titanium atoms in solid titaniumcatalyst component (I).

When an electron donor selected from electron donor (IV), electron donor(V), and electron donor (VI) is used in the amount specified above inthe main polymerization, the process is preferable since a polymerhaving high tacticity and crystallinity can be produced withoutsignificant decrease in the polymerization activity.

By using hydrogen in the main polymerization, the molecular weight ofthe resulting polymer can be regulated, yielding a polymer having a highmelt flow rate.

In the present invention, the temperature and pressure for olefinpolymerization depend on the polymerization method and the monomer(s) tobe polymerized, but the temperature is generally 10 to 200° C. andpreferably 30 to 150° C., and the pressure is generally normal pressureto 5 MPa and preferably 0.05 to 4 MPa.

In the polymerization process of the present invention, thepolymerization may be performed in any of batch, semi-continuous, andcontinuous modes. The polymerization may be performed in two or moresteps with different reaction conditions.

By polymerizing or copolymerizing mainly (a) C₃ or higher α-olefin(s)with the above polymerization catalyst, there can be obtained a polymerwhose melt flow rate (MFR) is 0.001 to 200 g/10 min, and preferably 0.01to 100 g/10 min.

The polymer obtained by the process for producing an olefin polymer ofthe present invention has high tacticity, and although the propertiesdepend on the olefin(s) used, the polymer has well-balanced heatresistance, transparency, formability, and mechanical strength. Inparticular, 4-methyl-1-pentene can be polymerized to yield a resin withwell-balanced heat resistance and transparency, and copolymerizationwith the above olefin(s) also works well.

The olefin polymer thus obtained may be blended with a heat stabilizer,weathering stabilizer, antistatic agent, anti-blocking agent, lubricant,nucleating agent, pigment, dye, inorganic or organic filler, or the likeas needed.

[4-Methyl-1-Pentene-Based Polymer (1)]

The present invention using the above olefin polymerization catalyst caneasily provide, for example,

a 4-methyl-1-pentene-based polymer containing 80 to 99.9 mass % ofstructural units derived from 4-methyl-1-pentene (A₁) and 0.1 to 20 mass% of structural units derived from at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene (B₁), wherein

the ratio of the content of structural units derived from the at leastone C₃₋₁₁ α-olefin(s) except 4-methyl-1-pentene in the n-decane-solublecomponent, a₁ in mass %, to the content of structural units derived from4-methyl-1-pentene in said olefin polymer, b₁ in mass %, (a₁/b₁) is 2.0to 4.0.

In the present invention, as the at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene (B₁), preferred are C₆₋₁₀ α-olefins, and morepreferred are C₈₋₁₀ α-olefins. Specifically, preferred are 1-hexene,1-pentene, 1-octene, 1-nonene, and 1-decene, and more preferred are1-octene, 1-nonene, and 1-decene.

When the above α-olefin(s) is/are used as the at least one C₃₋₁₁α-olefin except 4-methyl-1-pentene, the copolymerization nicely proceedsand provides a copolymer having excellent toughness.

In the 4-methyl-1-pentene-based polymer, the content of structural unitsderived from 4-methyl-1-pentene (A₁) is preferably in the range of 80.0to 99.9 mass %, and more preferably 96.0 to 98.0 mass %. In the4-methyl-1-pentene-based polymer, the content of structural unitsderived from the at least one C₃₋₁₁ α-olefin (B₁) except4-methyl-1-pentene is preferably in the range of 0.1 to 20.0 mass %, andmore preferably 2.0 to 4.0 mass %.

In the 4-methyl-1-pentene-based polymer, when the content of structuralunits derived from 4-methyl-1-pentene and the content of structuralunits derived from the at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene are in the above ranges, a film formed from saidcopolymer is excellent in releasability and toughness.

The content of structural units derived from the C₃₋₁₁ α-olefin (s)except 4-methyl-1-pentene in the n-decane-soluble component of the4-methyl-1-pentene-based polymer, a₁ (mass %), can be determined bynuclear magnetic resonance (NMR) measurement. For example, for acopolymer of 4-methyl-1-pentene and (a) C₃ or higher α-olefin(s), theNMR spectrum is recorded under the following conditions.

NMR spectrometer: GSX-400, manufactured by JEOL Ltd.

Solvent: benzene-d₆/o-dichlorobenzene mixed solvent

Sample concentration: 50 to 100 g/liter-solvent

Measurement condition: Pulse interval 5.5 sec; Scan number 16000;measurement temperature 120° C.

The peak area is obtained for each of the following signals in the¹³C-NMR spectrum recorded under the above conditions to calculate themolar content of structural units derived from the α-olefin except4-methyl-1-pentene in the copolymer using the following equation. Themass content, a₁ (mass %), can be obtained by converting the molarcontent using the molecular weights of the α-olefins composing thecopolymer.α-Olefin content (mol %)=[P2/(P1+P2)]×100P1: around 46 ppm, assigned to the side-chain CH₂ in 4-methyl-1-pentene,represented by (P1) in the following formula.P2: assigned to the comonomer's side-chain CH₂ or CH₃ directly bonded tothe main-chain methylene, represented by (P2) in the following formula.

The chemical shift of P2 depends on the structure of α-olefin comonomer:21 ppm for propylene, 27 ppm for 1-butene, and around 35 ppm for1-hexene and higher linear α-olefins. The α-olefin copolymer can beidentified based on the ratio of absorption intensity at around 35 ppmand that at around 30 ppm.

The content of structural units derived from the C₃₋₁₁ α-olefin (s)except 4-methyl-1-pentene in the 4-methyl-1-pentene-based polymer, b₁(mass %), can be determined similarly to the above method fordetermining a₁, the content of structural units derived from the C₃₋₁₁α-olefin (s).

The present invention is characterized in that the ratio of a₁ (mass %)to b₁ (mass %) (a₁/b₁) is in the range of 2.0 to 4.0.

In copolymers of 4-methyl-1-pentene and at least one C₃₋₁₁ α-olefinexcept 4-methyl-1-pentene, generally a close relationship is observedbetween the content of structural units derived from the at least oneC₃₋₁₁ α-olefin except 4-methyl-1-pentene in the n-decane-solublecomponent and the releasability of a formed article obtained from thecopolymer, for example, the blocking factor of a film. With increase ofthis content in the n-decane-soluble component, the releasability of theformed article tends to deteriorate, for example, the blocking factor ofthe film obtained tends to increase.

In the above copolymers, on the other hand, the content of structuralunits derived from the at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene in the copolymer generally has a strong relationshipwith the toughness and handleability of a film obtained therefrom. Withdecrease of this content in the copolymer, the mechanical property ofthe film, for example, the toughness is lowered. Such a film tends tocause difficulty in handling such as occurrence of break or crack onreeling or cutting the film.

Accordingly, the ratio a₁/b₁ is an important index for producing apolymer capable of forming a film having a low blocking factor,excellent mechanical properties, and excellent handleability. With theabove range of the ratio a₁/b₁, a polymer can provides a formed articleexcellent in not only releasability but also mechanical properties suchas toughness. Such a polymer provides, for example, a film having a lowblocking factor and high toughness.

Further, such polymer can provide a film having good releasability evenwith increasing absolute content of the structural unit derived from theat least one C₃₋₁₁ α-olefin except 4-methyl-1-pentene in then-decane-soluble component. For example, when this film is used as arelease film, the releasability is good and the amount of materialstransferred from the release film to the substrate is reduced ascompared with conventional films.

The ratio a₁/b₁ is preferably in the range of 2.0 to 4.0, and morepreferably 2.5 to 4.0. With this range of a₁/b₁, a film having goodreleasability and excellent toughness can be obtained.

In terms of surface stickiness, releasability, and strength of formedarticles, it has been considered so far that formed articles such asfilms obtained from a 4-methyl-1-pentene-based polymer exhibit betterperformances when the polymer has a lower molar content of structuralunits derived from (a) C₃₋₁₁ α-olefin(s) except 4-methyl-1-pentene inits n-decane-soluble component. Namely, it has been considered that thepolymer with lower a₁/b₁ exhibits preferred performances in the aboveaspects. However, 4-methyl-1-pentene-based polymer (1) of the presentinvention surprisingly exhibits desirable performances in a relativelyhigh range of a₁/b₁. Although the reason for this tendency is notclarified, this is likely because the polymer of the present inventionhas high tacticity and quite uniform distribution of structural unitsderived from the C₃₋₁₁ α-olefin(s). Namely, it is likely that4-methyl-1-pentene-based polymer (1) of the present invention ischaracterized in that its n-decane-soluble component contains onlypolymers having structural units derived from the C₃₋₁₁ α-olefin(s) in ahigher content than conventional polymers, and hence exhibits the abovepreferred range of a₁/b₁.

The ratio a₁/b₁ can be controlled as follows:

4-Methyl-1-pentene (A₁) and the at least one C₃₋₁₁ α-olefin except4-methyl-1-pentene (B₁) are copolymerized in such a manner that the4-methyl-1-pentene-based polymer contains 0.1 to 20 mass %, preferably 2to 4 mass %, of structural units derived from at least one C₃₋₁₁α-olefin except 4-methyl-1-pentene (B₁) using the olefin polymerizationcatalyst of the present invention, which contains the specific solidtitanium catalyst component (I) and organometallic catalyst component(II), thereby a₁/b₁ can be controlled.

The ratio a₁/b₁ can be also controlled using electron donors (IV) to(VI) together with solid titanium catalyst component (I) andorganometallic catalyst component (II).

[4-Methyl-1-Pentene-Based Polymer (2)]

In the present invention, using the above olefin polymerizationcatalyst, there can be easily produced 4-methyl-1-pentene-based polymer(2) containing 80 to 99.9 mass % of structural units derived from4-methyl-1-pentene (A₂) and 0.1 to 20 mass of structural units derivedfrom at least one C₁₂₋₂₀ α-olefin (B₂), wherein the ratio of the contentof structural units derived from the C₁₂₋₂₀ α-olefin(s) in itsn-decane-soluble component, a₂ in mass %, to the content of structuralunits derived from the at least one C₁₂₋₂₀ olefin(s) in the olefinpolymer, b₂ in mass %, (a₂/b₂) is 3.0 to 6.0.

In the present invention, the at least one C₁₂₋₂₀ α-olefin (B₂) ispreferably a C₁₂₋₁₈ α-olefin. Specifically, preferred are 1-dodecene,1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-octadecene,1-nonadecene, and 1-eicosene, and more preferred are 1-dodecene,1-tetradecene, 1-hexadecene, and 1-octadecene.

When the above α-olefin(s) is/are used as the at least one C₁₂₋₂₀α-olefin, copolymerization nicely proceeds and yields a copolymerexcellent in toughness.

In the 4-methyl-1-pentene-based polymer, the content of structural unitsderived from 4-methyl-1-pentene (A₂) is preferably 80.0 to 99.9 mass %,and more preferably 92.0 to 98.0 mass %, while the content of structuralunits derived from the at least one C₁₂₋₂₀ α-olefin (B₂) is preferably0.1 to 20.0 mass %, and more preferably 2.0 to 8.0 mass %.

In the 4-methyl-1-pentene-based polymer, when the content of structuralunits derived from 4-methyl-1-pentene and the content of structuralunits derived from the at least one C₁₂₋₂₀ α-olefin are in the aboveranges, a film having excellent releasability and toughness can beattained.

The content of structural units derived from the one C₁₂₋₂₀ α-olefin inthe n-decane-soluble component of the 4-methyl-1-pentene-based polymer,a₂ (mass %), can be determined similarly to the content of structuralunits derived from (a) C₃₋₁₁ α-olefin(s), a₁.

The content of structural units derived from the C₁₂₋₂₀ α-olefin(s) inthe 4-methyl-1-pentene-based polymer, b₂ (mass %), can be determinedsimilarly to the content of structural units derived from (a) C₃₋₁₁α-olefin(s), b₁.

The present invention is characterized in that the ratio of a₂ in mass %to b₂ in mass % (a₂/b₂) is in the range of 3.0 to 6.0.

In a copolymer of 4-methyl-1-pentene and the at least one C₁₂₋₂₀α-olefin, generally, the content of structural units derived from the atleast one C₁₂₋₂₀ α-olefin in the n-decane-soluble component has a closerelationship to the releasability of formed articles, for example, theblocking factor of films obtained from the copolymer. As this content inthe n-decane-soluble component increases, the copolymer tends to giveformed articles with inferior releasability, for example, films withhigher blocking factor.

In the above copolymer, on the other hand, the content of structuralunits derived from the at least one C₁₂₋₂₀ α-olefin in the copolymergenerally has a close relationship to the toughness and handleability ofthe film. As this content in the copolymer decreases, the film degradesin mechanical properties, for example, toughness. Such a film tends tocause difficulty in handling such as occurrence of break or crack onreeling or cutting the film.

Accordingly, the ratio a₂/b₂ is an important index for producing apolymer capable of proving films having a low blocking factor andexcellent mechanical properties and handleability. A polymer with theabove range of a₂/b₂ can provide formed articles excellent in not onlyreleasability but also mechanical properties such as toughness. Such apolymer provides, for example, films having a low blocking factor andhigh toughness.

Such a polymer can provide a film with good releasability even with ahigher absolute content of structural units derived from the at leastone C₁₂₋₂₀ α-olefin in its n-decane-soluble component. For example, whenthis film is used as a release film, the releasability is good and theamount of materials transferred from the release film to the substrateis reduced as compared with conventional films.

The ratio a₂/b₂ is preferably in the range of 3.0 to 6.0, and morepreferably 4.0 to 6.0. With this range of a₂/b₂, films with goodreleasability and excellent toughness can be obtained.

In terms of surface stickiness, releasability, and strength of formedarticles, it has been so far considered that formed articles such asfilms obtained from a 4-methyl-1-pentene-based polymer exhibit betterperformances when the molar content of structural units derived from (a)C₁₂₋₂₀ α-olefin(s) except 4-methyl-1-pentene in the n-decane-solublecomponent of the polymer. Namely, it has been considered that thepolymer with lower a₂/b₂ exhibits preferred performances in the aboveaspects. However, 4-methyl-1-pentene-based polymer (2) of the presentinvention surprisingly exhibits preferable performances in a relativelyhigh range of a₂/b₂. Although the reason for this tendency is notclarified, this is likely because the polymer of the present inventionhas high tacticity and quite uniform distribution of structural unitsderived from the C₁₂₋₂₀ α-olefin(s). Namely, it is likely that4-methyl-1-pentene-based polymer (2) of the present invention has afeature that its n-decane-soluble component contains only polymerscontaining structural units derived from the C₁₂₋₂₀ α-olefin(s) in ahigher content than conventional polymers, and hence exhibits the abovepreferred range of a₂/b₂.

The ratio a₂/b₂ can be controlled as follows:

4-Methyl-1-pentene (A₂) and the at least one C₁₂₋₂₀ α-olefin except4-methyl-1-pentene (B₂) are copolymerized in such a manner that thecontent of structural units derived from at least one C₁₂₋₂₀ α-olefinexcept 4-methyl-1-pentene (B₂) is 0.1 to 20 mass %, preferably 2 to 8mass %, in the 4-methyl-1-pentene-based polymer, using the olefinpolymerization catalyst of the present invention, which contains thespecific solid titanium catalyst component (I) and organometalliccatalyst component (II), thereby a₂/b₂ can be controlled.

The ratio a₂/b₂ can be also controlled using electron donors (IV) to(VI) together with solid titanium catalyst component (I) andorganometallic catalyst component (II).

[Film]

4-Methyl-1-pentene-based polymer (1) and 4-methyl-1-pentene-basedpolymer (2) obtained by the present invention can be formed into filmsexcellent in releasability and also transparency, heat resistance,anti-fogging property, appearance, and mechanical properties such astoughness.

The film of the present invention may be a single-layer film containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin or may be amulti-layer film having at least one layer containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin and (a)layer(s) made of (an)other resin(s) or the like.

The thickness of the above single-layer film is generally in the rangeof 20 to 100 μm, preferably 25 to 60 μm, and more preferably 40 to 60μm.

The whole thickness of the above multi-layer film is generally in therange of 40 to 200 μm, preferably 100 to 180 μm, and more preferably 120to 150 μm. In the multi-layer film, the total thickness of layerscontaining 4-methyl-1-pentene-based polymer (1) and/or4-methyl-1-pentene-based polymer (2) according to the present inventionas a resin is preferably 25% or more, more preferably 30% or more, andstill more preferably 40% or more, of the whole thickness of the film.

The process for producing the film from the polymer is not particularlylimited and includes, for example, T-die molding, extrusion molding suchas tubular extrusion (inflation molding), solution-casting, calendarmolding, and the like.

Among these, T-die molding is preferred for attaining uniformity of filmthickness.

The blocking factor of the film is generally in the range of 2.0 to 10.0g/cm, and preferably 2.0 to 7.0 g/cm.

The film having a blocking factor within the above range exhibitsextremely excellent releasability. For example, when the film is used asa release film for producing a flexible printed circuit board (FPC), itis quite easily peeled off from the printed circuit board which has beenpress-molded, and therefore this film can be suitably used as a releasefilm for producing FPC.

[4-Methyl-1-Pentene-Based Polymer Film (1)]

Forming 4-methyl-1-pentene-based polymer (1) of the present invention asdescribed above provides a film having a ratio c₁/d₁ of 0.1 to 1.5,wherein c₁ denotes the blocking factor (g/cm) of the film and d₁ denotesthe content (mol %) of structural units derived from (a) C₃₋₁₁α-olefin(s) except 4-methyl-1-pentene in the n-decane-soluble componentof 4-methyl-1-pentene-based polymer (1) used for forming the film.

So far, it has been believed that the molar content of structural unitsderived from (a) C₃₋₁₁ α-olefin(s) except 4-methyl-1-pentene in then-decane-soluble component of 4-methyl-1-pentene-based polymer (1)should be reduced in order to improve releasability of the film.However, decreasing this molar content generally tends to deterioratetoughness of the film as a whole. In contrast, the film having c₁/d₁within the above range exhibits excellent mechanical properties, forexample, toughness, and handleability in reeling, cutting, and the likeof the film even if the blocking factor itself is low.

The blocking factor c₁ of the film can be determined in accordance withASTM D1893-67. The content d₁ (mol %) of structural units derived fromthe C₃₋₁₁ α-olefin(s) except 4-methyl-1-pentene in the n-decane-solublecomponent of the 4-methyl-1-pentene-based polymer can be determined by¹³C-NMR measurement in the same manner as described above.

In the above range, c₁/d₁ is preferably from 0.2 to 1.0, and morepreferably from 0.3 to 0.8.

A film with c₁/d₁ in the above range exhibits good releasability andexcellent toughness.

The ratio c₁/d₁ can be controlled as follows:

In such a manner that the content of structural units derived from atleast one C₃₋₁₁ α-olefin except 4-methyl-1-pentene (B₁) becomes 0.1 to20 mass %, and preferably 2 to 4 mass % in the 4-methyl-1-pentene-basedcopolymer, 4-methyl-1-pentene (A₁) and the at least one C₃₋₁₁ α-olefinexcept 4-methyl-1-pentene (B₁) are copolymerized using the olefinpolymerization catalyst of the present invention containing the specificsolid titanium catalyst component (I) and organometallic catalystcomponent (II) to obtain a copolymer, and the copolymer is formed into afilm, thereby c₁/d₁ is controlled.

[4-Methyl-1-Pentene-Based Polymer Film (2)]

Forming the 4-methyl-1-pentene-based polymer (2) of the presentinvention as described above can provide a film having a ratio c₂/d₂ of0.1 to 1.5, wherein “c₂” denotes the blocking factor (g/cm) of the film,and “d₂” denotes the content (mol %) of structural units derived from(a) C₁₂₋₂₀ α-olefin(s) in the n-decane-soluble component of the4-methyl-1-pentene-based polymer (2) used for forming the film.

So far, it has been believed that the molar content of the structuralunits derived from the C₁₂₋₂₀ α-olefin(s) in the n-decane-solublecomponent of the 4-methyl-1-pentene-based polymer (2) should be reducedin order to improve the releasability of the film. However, decreasingthis molar content generally tends to deteriorate the toughness of thefilm as a whole. While on the other hand, the film having c₂/d₂ withinthe above range exhibits excellent mechanical properties, for example,toughness, and handleability in reeling, cutting, and the like of thefilm.

The blocking factor c₂ of the film can be determined in accordance withASTM D1893-67. The content d₂ (mol %) of structural units derived fromthe C₁₂₋₂₀ α-olefin(s) in the n-decane-soluble component of the4-methyl-1-pentene-based polymer can be determined by ¹³C-NMR in thesame manner as described above.

In the above range, c₂/d₂ is preferably 0.2 to 1.0, and more preferably0.3 to 0.8.

A film having c₂/d₂ within the above range exhibits good releasabilityand excellent toughness.

The ratio of c₂/d₂ can be controlled as follows:

4-methyl-1-pentene (A₂) and the at least one C₁₂₋₂₀ α-olefin except4-methyl-1-pentene (B₂) are copolymerized in such a manner that thecontent of structural units derived from at least one C₁₂₋₂₀ α-olefin(B₂) except 4-methyl-1-pentene becomes 0.1 to 20 mass %, and preferably2 to 8 mass % in the 4-methyl-1-pentene-based polymer, using the olefinpolymerization catalyst of the present invention containing the specificsolid titanium catalyst component (I) and organometallic catalystcomponent (II) to obtain a copolymer, and this copolymer is formed intoa film, thereby c₂/d₂ can be controlled.

The film of the present invention thus obtained is excellent inreleasability and also transparency, heat resistance, anti-foggingproperty, appearance, and mechanical properties such as toughness. Thefilm is suitably used as a release film for producing electronic circuitboards, release film for artificial leather, wrapping film foragriculture and foods, and baking carton. The film can be also used asone layer in unwoven fabric laminates or laminated paper, which is akind of laminate.

[Release Film]

4-Methyl-1-pentene-based polymer film (1) and 4-methyl-1-pentene-basedpolymer film (2) obtained as described above are excellent inreleasability, fouling resistance, moisture absorption resistance, andthe like. The films can be suitably used as release films, for example,release films for printed circuit boards, especially for flexibleprinted circuit boards.

In production processes of printed circuit boards, flexible printedcircuit boards, multi-layer printed circuit boards, and the like, arelease film is used in hot-pressing a copper-plated laminate board orcopper foil through a prepreg or heat-resistant film. Further, inproducing a flexible printed circuit board, when a coverlay film isbonded by hot-press with a thermosetting adhesive to a mother flexibleprinted circuit board with electronic circuit formed thereon,interposing a release film is a common method for preventing adhesionbetween the coverlay film and a hot-press plate. In producing pluralsingle-layer or multi-layer printed circuit boards at one time, releasefilms are also imposed for preventing adhesion of printed circuit boardsto each other and protecting printed circuit board products.

The conventional release films so far proposed include polymethylpentenefilms, silicone-coated polyester films, fluororesin films, syndiotacticpolystyrene films, alicyclic polyolefin films, polyamide films,polyether aromatic ketone resin films, and the like. However, theserelease films proposed had weakness in releasability from coverlay filmsor the like, particularly, poor plating due to materials from the filmsto copper foil in producing multi-layer flexible circuit boards.Further, with the recent growing social awareness to environmentalproblems and safety issues, these release films are increasinglyrequested to have moisture absorption resistance, rigidity, andanti-fouling property in addition to heat resistance compatible withhot-press molding and releasability from printed circuit boards(including polyimide resin, epoxy resin, epoxy resin adhesives, andcopper foil) or hot-press plates.

The release film of the present invention may be a single-layer filmcontaining 4-methyl-1-pentene-based polymer (1) and/or4-methyl-1-pentene-based polymer (2) according to the present inventionas a resin, or it may be a multi-layer film having a layer containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin and (a)layer(s) made of (an)other resin(s) or the like. In the multi-layerfilm, its outermost layer, which contacts with a substrate, for example,printed circuit board, is preferably a layer containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin, because thelayer made of the polymer(s) of the present invention is excellent inreleasability.

Particularly, for a release film used in producing flexible printedcircuit boards, considering cushioning function that the film is adheredin response to steps at boundaries between polyimide film and copperfoil to reduce the impact when pressed with hot-press (hereinafter,abbreviated as “adherence”), the release film is more preferably amulti-layer film, particularly a multilayer film whose outermost layercontacting to the printed circuit board is a layer containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin.

The thickness of the single-layer film is generally in the range of 3 to100 μm, but considering the production cost and handleability,preferably 10 to 100 μm, and more preferably 30 to 60 μm.

The whole thickness of the multi-layer film is generally in the range of50 to 300 μm, but considering the adherence and workability, preferably70 to 250 μm, and more preferably 100 to 200 μm.

In the multi-layer film, as described above, the outermost layercontacting to a substrate is preferably a layer containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin, and thethickness of the outermost layer is preferably 25% or more, morepreferably 30% or more, and further preferably 40% or more of the wholethickness of the film.

There is no particular limitation on the method for producing therelease film of the present invention. The film can be produced byextrusion molding, for example, tubular extrusion, which is also calledinflation molding.

When the release film is produced by tubular extrusion, in order toobtain a uniform film thickness, it is quite important to keep a parisonextruded out of the cylinder at a controlled temperature properlyselected from the range of 50 to 290° C. so as to prevent immediatecooling of the parison.

A multi-layer release film can be obtained by laminating a layercontaining 4-methyl-1-pentene-based polymer (1) and/or4-methyl-1-pentene-based polymer (2) according to the present inventionas a resin with (a) layer(s) containing (an) other resin(s) or the like.

The release film of the present invention may be also produced by T-diemolding. The film may be obtained as a nonoriented film, or it may beuni-axially or bi-axially oriented after the film is taken out of theT-die. Orientation is effective to increase strength and stiffness ofthe film.

As the method for laminating a film containing 4-methyl-1-pentene-basedpolymer (1) and/or 4-methyl-1-pentene-based polymer (2) according to thepresent invention as a resin and (a) layer(s) containing (an)otherresin(s) or the like, there may be mentioned, dry lamination andco-extrusion lamination.

In dry lamination, a single-layer film containing4-methyl-1-pentene-based polymer (1) and/or 4-methyl-1-pentene-basedpolymer (2) according to the present invention as a resin is firstlyproduced, a layer containing (an) other resin(s) or the like is extrudedthrough a T-die while that single-layer film is fed near the T-die fromabove and below, and these layers are laminated with a roll. This methodis effective particularly when the resin layers are largely differentfrom each other in melt viscosity.

On the other hand, co-extrusion lamination can laminate a layercontaining 4-methyl-1-pentene-based polymer (1) and/or4-methyl-1-pentene-based polymer (2) according to the present inventionas a resin and (a) layer(s) containing (an)other resin(s) or the likewith an extruder equipped with multi-layer dice in one step.Co-extrusion lamination is cost-effective, because multi-layerlamination can be completed in one step.

EXAMPLES

Hereinafter the present invention will be more specifically describedwith Examples, but the present invention is not limited to theseExamples.

The properties of solid titanium catalyst components and polymersobtained in Examples and Comparative Examples were determined by thefollowing methods.

[Composition of Solid Titanium Catalyst Component]

The titanium and magnesium contents were analyzed by plasma emissionspectrometry using ICPS7500 manufactured by Shimadzu Corporation.

The halogen content was determined by potentiometric titration with asilver nitrate solution using Hiranuma Automatic Titrator manufacturedby Hiranuma Sangyo Corporation.

The compound having two or more ether linkages represented by generalformula (1) was analyzed by conventional methods using gaschromatography (GC).

Specifically, 200 to 300 mg of a solid titanium catalyst component wasweighed and put in a 50-ml volumetric flask, acetone was added todissolve the solid titanium catalyst component, 50 μl of di-n-butylphthalate is added as an internal standard, and acetone was furtheradded to make the total volume 50 ml. This solution was neutralized withaqueous ammonia, filtered when solid was remained, and the filtrate wasused as a sample solution.

The sample solution was analyzed by gas chromatography (GC) under thefollowing conditions with GC-14A manufactured by Shimadzu Corporationwith a DB-WAX column (30-cm long) manufactured by Agilent Technologies.

Injection unit temperature: 250° C.

Column temperature: After sample injection, the column temperature waskept at 50° C. for 2 minutes, elevated to 230° C. at a heating rate of15° C./min, and kept at 230° C. for 20 minutes.

Carrier gas: Helium

Column flow rate: 1.1 ml/min

Sample injection volume: 1 μl

A calibration curve was obtained by conventional procedures usingacetone solutions containing di-n-butyl phthalate as an internalstandard and the ether compound represented by general formula (1) indifferent concentrations.

The content of the compound represented by general formula (1) in thesolid titanium catalyst component was calculated from the calibrationcurve and the observed response in GC analysis of the solid titaniumcatalyst component.

[Melt Flow Rate (MFR)]

Melt flow rate was measured at a load of 5 kg at 260° C. in accordancewith ASTM D1238.

In Example 12, MFR was measured at a load of 2.16 kg at 230° C.

[Apparent Bulk Density]

Each polymer was subjected to free-fall through a funnel into a cylinderhaving an inside volume of 100 ml. The apparent bulk density wasdetermined from the mass of the polymer in the cylinder and the cylindervolume.

[Amount of Polymer in Filtrate]

A polymer slurry obtained by polymerizing monomers in an inert solventwas filtered to separate into solid polymer (white solid) and filtrate.The polymer dissolved in the filtrate was obtained by removing thesolvent from the filtrate by evaporation. The amount of polymer in thefiltrate was calculated from the following equation.Amount of polymer in filtrate (mass %)=W2/(W1+W2)×100

W1: mass of solid polymer (white solid) filtered off

W2: mass of polymer dissolved in the filtrate of the slurry.

[Tacticity Index (t-II) and Content of Decane-Soluble Component]

Three grams of the solid polymer was weighed and completely dissolved inn-decane at 150° C., the solution was cooled to 23° C. over 8 hours andfiltered, and n-decane in the filtrate was evaporated to givedecane-soluble polymer, mass of which was measured. This value wasdivided by the mass of the solid polymer initially weighed to obtain thecontent of polymer dissolved in n-decane (w3: content of decane-solublecomponent). The mass of n-decane-soluble component was calculated fromthis content.W3=W1×w3/100

W1: mass of solid polymer

W3: mass of n-decane-soluble component in the solid polymer

w3: content of polymer dissolved in n-decane (mass %)

Tacticity index (t-II) was calculated using the following equation.Tacticity index (t-II) (mass %)=(W1−W3)/(W1+W2)×100

W1: mass of solid polymer

W2: mass of polymer dissolved in filtrate of the slurry

W3: mass of n-decane-soluble component in the solid polymer

Namely, t-II is an index to evaluate tacticity in terms of the massratio of decane-insoluble component to the total of the solid polymerand the polymer dissolved in the filtrate.

[Catalytic Activity]

The catalytic activity was determined by dividing the mass of the solidpolymer yielded per unit time by the amount of titanium atoms (inmillimoles) in the solid titanium catalyst component used for thepolymerization.

[Blocking Factor]

The blocking factor (g/cm) of the film was determined in accordance withASTM D1893-67 as follows: the polymer was formed with a cast-filmforming machine equipped with a T-die at a cylinder temperature of 310°C. and a chill-roll temperature of 60° C. into a 50-μm thick film, fromwhich two films, each 6 cm×12 cm in size, were cut out; these films werestacked together with their chill-roll sides facing to each other; thestack was sandwiched between two metal plates with mirror-finishedsurfaces, hot-pressed at 180° C. under a load of 5 MPa for 30 minutes,and then cooled to room temperature; and the stack was subjected to thepeeling test, in which shearing force was applied at a load of 200 g,with a shearing angle of 180°, at a shearing speed of 200 mm/min with aversatile material tester, Model-2001 manufactured by INTESCO Co., Ltd.,to measure the maximum load at separation.

[Molecular Weight Distribution (Mw/Mn)]

With a gel permeation chromatograph (GPC) (alliance 2000 manufactured byWaters Corporation), a GMH-type column manufactured by TosohCorporation, and o-dichlorobenzene as an eluent, the weight-averagemolecular weight (Mw) and number-average molecular weight (Mn) relativeto polystyrene were measured to obtain the value of Mw/Mn.

[Content of Structural Units Derived from C₃₋₁₁ α-Olefin Except4-Methyl-1-Pentene or C₁₂₋₂₀ α-Olefin in N-Decane-Soluble Component]

The content of structural units derived from (a) C₃₋₁₁ α-olefin(s)except 4-methyl-1-pentene or (a) C₁₂₋₂₀ α-olefin(s) in then-decane-soluble component was determined by nuclear magnetic resonance(NMR).

NMR spectrometer: GSX-400, manufactured by JEOL Ltd.

Solvent: benzene-d₆/o-dichlorobenzene mixed solvent

Sample concentration: 50 to 100 g/liter-solvent

Measurement conditions: Pulse interval 5.5 sec; Scan number 16000;Measurement temperature 120° C.

The peak area was obtained for each of the following signals in the¹³C-NMR spectrum recorded under the above conditions to calculate themolar content (mol %) of structural units derived from the α-olefin(s)except 4-methyl-1-pentene in the copolymer using the following equation.The mass content (mass %) was calculated from the molar content and themolecular weights of α-olefins corresponding to the structural units.Comonomer content (mol %)=[P2/(P1+P2)]×100P1: around 46 ppm, side-chain CH₂ in 4-methyl-1-pentene (represented by(P1) in the following formula)P2: comonomer's side-chain CH₂ directly bonded to the main-chainmethylene (represented by (P2) in the following formula)

The chemical shift of P2 depends on the structure of α-olefin comonomer:21 ppm for propylene, 27 ppm for 1-butene, and around 35 ppm for1-hexene and higher linear α-olefins. The α-olefin copolymer can beidentified based on the ratio of absorption intensity around 35 ppm andthat around 30 ppm.

[Content of Structural Units Derived from C₃₋₁₁ α-Olefin Except4-Methyl-1-Pentene or C₁₂₋₂₀ α-Olefin in Polymer]

The content was determined by ¹³C-NMR similarly to the content ofstructural units derived from the C₃₋₁₁ α-olefin(s) except4-methyl-1-pentene or the C₁₂₋₂₀ α-olefin(s) in the n-decane-solublecomponent.

[Melting Point (Tm)]

With a differential scanning calorimeter (DSC), Model PYRIS-Imanufactured by PerkinElmer, Inc., under a nitrogen atmosphere, 5 mg ofa sample was heated at 280° C. for 5 minutes to melt, cooled to roomtemperature at a cooling rate of 20° C./min to crystallize, kept at roomtemperature for 10 minutes, and heated at a heating rate of 10° C./minto obtain an endothermic curve, in which the peak temperature wasregarded as the melting point.

[Tensile Elongation at Break] (Toughness)

The polymer was formed into a 2 mm-thick dumbbell specimen of ASTMtype-IV with an injection-molding machine, M70B manufactured by MEIKICo., Ltd., at a cylinder temperature of 290° C. and a mold temperatureof 60° C.

The dumbbell specimen obtained was subjected to the tensile test tomeasure the tensile elongation at break, in accordance with ASTM D638,at a tensile speed of 50 mm/min with a versatile material testerModel-2005 manufactured by INTESCO Co., Ltd.

Example 1 Preparation of Solid Titanium Catalyst Component [A-1]

Seventy-five grams of anhydrous magnesium chloride, 280.3 g of decane,and 308.3 g of 2-ethylhexyl alcohol were heated at 130° C. for 3 hoursto proceed the reaction, thereby a homogeneous solution was obtained. Tothis solution was added 18.5 g of2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP), and the solution wasfurther stirred at 100° C. for 1 hour.

The homogeneous solution thus obtained was cooled to room temperature,and 30 ml of this homogeneous solution was injected dropwise over 45minutes into 80 ml of titanium tetrachloride that was kept at −20° C.and stirred. The temperature of the liquid mixture was elevated to 110°C. over 5.8 hours, here was added 0.42 g of2-methyl-2-n-propyl-1,3-diethoxypropane, and the solution was stirred atthe same temperature for 2 hours. After completion of the reaction for 2hours, the mixture was filtered in hot to collect the solid. This solidwas again suspended in 100 ml of titanium tetrachloride, and thesuspension was heated again at 110° C. for 2 hours to react. After thereaction, the mixture was filtered in hot to collect the solid, and thesolid was washed thoroughly with 90° C. decane and hexane until no freetitanium compound was detected in the washing. The solid titaniumcatalyst component [A-1] prepared by the above procedures was stored asa decane slurry. Part of the slurry was dried to analyze the catalystcomposition. Solid titanium catalyst component [A-1] thus obtainedcontained 3.6 mass % of Ti, 18 mass % of Mg, 56 mass % of Cl, 10.6 mass% of 2-methyl-2-n-propyl-1,3-diethoxypropane, and 2.3 mass % of2-ethylhexyl alcohol residue.

[Polymerization]

In dry nitrogen stream at room temperature, a 1-liter polymerizationreactor was charged with 400 ml of 4-methyl-1-pentene (dried overactivated alumina under dry nitrogen), 300 ml of hydrogen, 0.5 mmol oftriethylaluminum, and 0.0016 mmol (in terms of Ti) of solid titaniumcatalyst component [A-1]. The inside of the reactor was kept at 60° C.,and the polymerization was performed for 1 h. After that, the powder wastaken out of the reactor through filtration, washed with hexane, anddried overnight under reduced pressure at 80° C. to yield 113.9 g of apolymer. The properties of the polymer obtained were evaluated. Theresults are shown in Table 1.

Example 2

Polymerization was performed similarly to Example 1 to yield 85.4 g of apolymer. Here, 4 ml of 1-decene was added as a comonomer besides 400 mlof 4-methyl-1-pentene, and the polymerization temperature was 50° C. Theproperties of the polymer obtained were evaluated. The results are shownin Table 1.

Example 3 Prepolymerization on Solid Titanium Catalyst Component [A-1]

In a 200-ml four-necked glass reactor with a stirrer, in dry nitrogenstream, were charged 8.36 ml of dry decane and 1.66 ml of a decanesolution (1.0 mol/l in terms of Al) of triethylaluminum. Here were added26.5 ml of a decane slurry of solid titanium catalyst component [A-1](containing solid titanium catalyst component [A-1] in an amount of 0.83mmol in terms of Ti, or 1.1 g in terms of mass) and 4.98 ml (3.3 g) of3-methyl-1-pentene. The mixture was stirred for 45 minutes while thetemperature was kept at 20° C. to obtain prepolymerized catalyst [A-1],which contained 3 g of a polymer per gram of solid titanium catalystcomponent [A-1].

[Polymerization]

Polymerization was performed similarly to Example 2 except thatprepolymerization catalyst [A-1] was used in place of solid titaniumcatalyst component [A-1] to yield 77.3 g of a polymer. The properties ofthe polymer obtained were evaluated. The results are shown in Table 1.

Example 4

Polymerization was performed similarly to Example 1, except that 0.0028mmol (in terms of Ti) of solid titanium catalyst component [A-1] wasused, 4 ml of 1-decene was added as a comonomer besides 400 ml of4-methyl-1-pentene, 0.5 mmol of 2-methyl-2-n-propyl-1,3-diethoxypropane(MPEP) was further added, and the polymerization temperature was 50° C.,to yield 54.6 g of a polymer. The properties of the polymer obtainedwere evaluated. The results are shown in Table 1.

Example 5

Polymerization was performed similarly to Example 1, except that 0.0036mmol (in terms of Ti) of solid titanium catalyst component [A-1] wasused, 4 ml of 1-decene was added as a comonomer besides 400 ml of4-methyl-1-pentene, 0.5 mmol of cyclohexylmethyldimethoxysilane (CMMS)was further added, and the polymerization temperature was 50° C., toyield 57.1 g of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 1.

Example 6 Preparation of Solid Titanium Catalyst Component [A-2]

Solid titanium catalyst component [A-2] was prepared similarly toExample 1 except that no 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP)was added after the heating to 110° C. in preparing solid titaniumcatalyst component [A-1] in Example 1. Solid titanium catalyst component[A-2] thus obtained contained 4.4 mass % of Ti, 18.0 mass % of Mg, 56mass % of Cl, 9.5 mass % of 2,2-diethyl-1,3-diethoxypropane, and 1.8mass % of 2-ethylhexyl alcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1, except that solidtitanium catalyst component [A-2] was used, 4 ml of 1-decene was addedas a comonomer besides 400 ml of 4-methyl-1-pentene, and thepolymerization temperature was 50° C., to yield 87.7 g of a polymer. Theproperties of the polymer obtained were evaluated. The results are shownin Table 1.

Example 7 Preparation of Solid Titanium Catalyst Component [A-3]

Solid titanium catalyst component [A-3] was prepared similarly toExample 1 except that 18.5 g of 2,2-diethyl-1,3-diethoxypropane (DEEP)was used in place of 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) andthat 0.42 g of 2,2-diethyl-1,3-diethoxypropane was added after theheating to 110° C. in preparing solid titanium catalyst component [A-1]in Example 1. Solid titanium catalyst component [A-3] thus obtainedcontained 3.6 mass % of Ti, 19.0 mass % of Mg, 56 mass % of Cl, 8.9 mass% of 2,2-diethyl-1,3-diethoxypropane, and 1.7 mass % of 2-ethylhexylalcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1 except that solidtitanium catalyst component [A-3] was used in place of [A-1] to yield90.4 g of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 1.

Example 8

Polymerization was performed similarly to Example 1, except that solidtitanium catalyst component [A-3] was used, 4 ml of 1-decene was addedas a comonomer besides 400 ml of 4-methyl-1-pentene, and thepolymerization temperature was 50° C., to yield 83.8 g of a polymer. Theproperties of the polymer obtained were evaluated. The results are shownin Table 1.

Example 9

Polymerization was performed similarly to Example 1, except that solidtitanium catalyst component [A-3] was used, 4 ml of 1-decene was addedas a comonomer besides 400 ml of 4-methyl-1-pentene, 0.05 mmol ofcyclohexylmethyldimethoxysilane (CMMS) was further added as anorganosilicon compound, and the polymerization temperature was 50° C.,to yield 58.7 g of a polymer. The properties of the polymer obtainedwere evaluated. The results are shown in Table 1.

Example 10 Preparation of Solid Titanium Catalyst Component [A-4]

Solid titanium catalyst component [A-4] was prepared similarly toExample 1 except that 19.9 g of 2-methyl-2-n-butyl-1,3-diethoxypropane(BMEP) was used in place of 2-methyl-2-n-propyl-1,3-diethoxypropane(MPEP) and that 0.48 g of 2-methyl-2-n-butyl-1,3-diethoxypropane wasused after the heating to 110° C. in preparing solid titanium catalystcomponent [A-1] in Example 1. Solid titanium catalyst component [A-4]contained 3.8 mass % of Ti, 18.0 mass % of Mg, 57 mass % of Cl, 11.6mass % of 2-methyl-2-n-butyl-1,3-diethoxypropane, and 1.4 mass % of2-ethylhexyl alcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1, except that solidtitanium catalyst component [A-4] was used, 4 ml of 1-decene was addedas a comonomer besides 400 ml of 4-methyl-1-pentene, and thepolymerization temperature was 50° C., to yield 84 g of a polymer. Theproperties of the polymer obtained were evaluated. The results are shownin Table 1.

Example 11 Preparation of Solid Titanium Catalyst Component [A-5]

Solid titanium catalyst component [A-5] was prepared similarly toExample 1 except that 17.1 g of2-methyl-2-n-propyl-1-methoxy-3-ethoxypropane (MPEMP) was used in placeof 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) and that 0.39 g of2-methyl-2-n-propyl-1-methoxy-3-ethoxypropane was used after the heatingto 110° C. in preparing solid titanium catalyst component [A-1] inExample 1. Solid titanium catalyst component [A-5] thus obtainedcontained 2.8 mass % of Ti, 18 mass % of Mg, mass % of Cl, 13.1 mass %of 2-methyl-2-n-propyl-1-methoxy-3-ethoxypropane, and 1.2 mass % of2-ethylhexyl alcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1, except that solidtitanium catalyst component [A-5] was used, 4 ml of 1-decene was addedas a comonomer besides 400 ml of 4-methyl-1-pentene, and thepolymerization temperature was 50° C., to yield 57 g of a polymer. Theproperties of the polymer obtained were evaluated. The results are shownin Table 1.

Example 12

A 1-liter polymerization reactor was charged with 400 ml of heptane, 75ml of hydrogen, 0.5 mmol of triethylaluminum, 0.05 mmol ofcyclohexylmethyldimethoxysilane (CMMS), and 0.004 mmol (in terms of Ti)of solid titanium catalyst component [A-3] obtained in Example 3.Polymerization was performed for 1 h while inside of the reactor waskept at 70° C. and propylene was fed at a gauge pressure of 0.5 MPa. Thepowder was taken out of the reactor through filtration, washed withhexane, and dried overnight under reduced pressure at 80° C. to yield55.6 g of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 1.

Comparative Example 1 Preparation of Solid Titanium Catalyst Component[A-6]

Preparation of solid titanium catalyst component [A-6] was triedsimilarly to Example 6 except that 17.1 g of2-methyl-2-ethyl-1,3-diethoxypropane (EMEP) was used in preparing solidtitanium catalyst component [A-2] in Example 6. However, no solidtitanium catalyst component was obtained, because the catalyst componentwas emulsified and isolation of solid by hot filtration was impossible.

Comparative Example 2 Preparation of Solid Titanium Catalyst Component[A-7]

Solid titanium catalyst component [A-7] was prepared similarly toExample 6 except that 22.7 g of2-isobutyl-2-isopropyl-1,3-diethoxypropane (BPEP) was used in place of2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) in preparing solidtitanium catalyst component [A-2] in Example 6. Solid titanium catalystcomponent [A-7] thus obtained contained 5.3 mass % of Ti, 18.0 mass % ofMg, 57 mass % of Cl, 3.2 mass % of2-methyl-2-n-propyl-1,3-diethoxypropane, and 1.4 mass % of 2-ethylhexylalcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1 except that 0.004mmol (in terms of Ti) of solid titanium catalyst component [A-7] wasused to yield 102.4 g of a polymer. The properties of the polymerobtained were evaluated. The results are shown in Table 2.

Comparative Example 3

Polymerization was performed similarly to Example 1, except that 0.004mmol (in terms of Ti) of solid titanium catalyst component [A-7] wasused and 4 ml of 1-decene was added as a comonomer besides 400 ml of4-methyl-1-pentene and the polymerization temperature was 50° C., toyield 83.2 g of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 2.

Comparative Example 4 Preparation of Solid Titanium Catalyst Component[A-8]

Preparation of solid titanium catalyst component [A-8] was triedsimilarly to Example 6 except that 24.0 g of2-isobutyl-2-isopentyl-1,3-diethoxypropane (BPNEP) was used in place of2-methyl-2-n-propyl-1,3-diethoxypropane in preparing solid titaniumcatalyst component [A-2] in Example 6. However, no solid titaniumcatalyst component was obtained because the reaction system wasemulsified and isolation of solid by hot filtration was impossible.

Comparative Example 5 Preparation of Solid Titanium Catalyst Component[A-9]

Solid titanium catalyst component [A-9] was prepared similarly toExample 6 except that 19.9 g of2-isobutyl-2-isopropyl-1,3-dimetoxypropane (BPMP) was used in place of2-methyl-2-n-propyl-1,3-diethoxypropane in preparing solid titaniumcatalyst component [A-2] in Example 6. Solid titanium catalyst component[A-9] thus obtained contained 4.1 mass % of Ti, 17.0 mass % of Mg, 57mass % of Cl, 15.9 mass % of2-isobutyl-2-isopropyl-1,3-dimethoxypropane, and 2.1 mass % of2-ethylhexyl alcohol residue.

[Polymerization]

Polymerization was performed similarly to Example 1 except that 0.004mmol (in terms of Ti) of solid titanium catalyst component [A-9] wasused to yield 108.8 g of a polymer. The properties of the polymerobtained were evaluated. The results are shown in Table 2.

Comparative Example 6

Polymerization was performed similarly to Example 1, except that 0.004mmol (in terms of Ti) of solid titanium catalyst component [A-9] wasused, 4 ml of 1-decene was added as a comonomer besides 400 ml of4-methyl-1-pentene, and the polymerization temperature was 50° C., toyield 99.8 g of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 2.

TABLE 1 Examples 1 2 3 4 5 6 7 C₃ or higher α-olefin (1)4-Methyl-1-pentene olefin α-olefin (2) — 1-Decene 1-Decene 1-Decene1-Decene 1-Decene — Solid titanium Designation A-1 A-1 A-1 A-1 A-1 A-2A-3 catalyst Ether (general MPEP MPEP MPEP MPEP MPEP MPEP DEEP component(I) formula (1)) Main Ether (general — — — MPEP — — — polymerizationformula (3)) Electron donor — — — — CMMS — — (IV) Catalytic activity71.2 53.4 48.3 19.5 15.9 54.8 56.5 (kg/mmol-Ti/hr) Polymer Apparent bulk340 350 360 410 410 330 390 (white solid) density (kg/m³) MFR (g/10 min)0.12 0.23 0.24 0.07 0.23 0.33 0.01 Content of 3.2 4.6 5.5 2.5 3.4 7.63.4 n-decane-soluble component (%) Content of — 2.9 3.2 3.7 3.7 2.6 —structural units derived from α-olefin (2): b₁ (wt %) Polymer content infiltrate (wt %) 1.4 2.3 1.2 0.7 0.9 2.6 1.9 Tacticity (t-II) (wt %) 95.493.2 93.4 96.8 95.7 90.0 94.8 Content of structural units — 7.6 8.2 11.311.8 6.5 — derived from α-olefin (2) in n-decane-soluble component: a₁(wt %) a₁/b₁ — 2.6 2.6 3.1 3.2 2.5 — Examples 8 9 10 11 12 C₃ or higherα-olefin (1) 4-Methyl-1-pentene Propylene olefin α-olefin (2) 1-Decene1-decene 1-Decene 1-Decene — Solid titanium Designation A-3 A-3 A-4 A-5A-3 catalyst Ether (general DEEP DEEP BMEP MPEMP DEEP component (I)formula (1)) Main Ether (general — — — — — polymerization formula (3))Electron donor — CMMS — — CMMS (IV) Catalytic activity 52.4 36.7 52.535.6 13.9 (kg/mmol-Ti/hr) Polymer Apparent bulk 350 380 350 300 390(white solid) density (kg/m³) MFR (g/10 min) 0.3 0.36 0.05 0.22 13.5Content of 6.9 3.5 6.2 4.9 3.5 n-decane-soluble component (%) Content of2.5 3.2 2.9 3.2 — structural units derived from α-olefin (2): b₁ (wt %)Polymer content in filtrate (wt %) 3.5 2 4.8 2 1.26 Tacticity (t-II) (wt%) 89.8 94.6 89.3 92.2 95.3 Content of structural units 6.4 9.4 7.0 8.1— derived from α-olefin (2) in n-decane-soluble component: a₁ (wt %)a₁/b₁ 2.6 2.9 2.4 2.5 —

TABLE 2 Comparative Examples 1 2 3 4 5 6 C₃ or higher α-olefin (1)4-Methyl-1-pentene olefin α-olefin (2) — — 1-Decene — — 1-Decene Solidtitanium Designation A-6 A-7 A-7 A-8 A-8 A-9 catalyst Ether (generalEMEP BPEP BPEP BPNEP BPMP BPMP component (I) formula (1)) Main Ether(general — — — — — — polymerization formula (3)) Electron donor — — — —— — (IV) Catalytic activity *1 25.6 20.8 *1 27.2 25 (kg/mmol-Ti/hr)Polymer Apparent bulk 340 330 380 360 (white solid) density (kg/m³) MFR(g/10 min) 0.29 0.47 0.15 0.25 Content of 14.7 19.7 5.3 7.3n-decane-soluble fraction (wt %) Content of — 2.4 — 2.8 structural unitsderived from α-olefin (2): b₁ (wt %) Polymer content in filtrate (%) 1916.2 5.1 6.4 Tacticity (t-II) (%) 69.1 67.3 89.9 86.8 Content ofstructural units — 4.4 — 5.3 derived from α-olefin (2) inn-decane-soluble component: a₁ (wt %) a₁/b₁ — 1.8 — 1.9 *1 Solidtitanium catalyst component is not obtained.

Example 13 Polymerization

At room temperature, a 290-liter polymerization reactor was charged with84.2 kg of 4-methyl-1-pentene, 100 liters of hydrogen, and thentriethylaluminum, 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP), andsolid titanium catalyst component [A-1] on which 4 g of3-methyl-1-pentene was prepolymerized per millimole of Ti. Thepolymerization was performed for 4 hours while the inside of the reactorwas kept at 48° C. The reaction mixture was washed with4-methyl-1-pentene/methanol mixture, the supernatant was removed, andthe powder was isolated with a decanter to yield 21 kg of a polymer. Theproperties of the polymer obtained were evaluated. The results are shownin Table 3.

[Film Production]

Poly-4-methyl-1-pentene obtained above was mixed with a knownneutralizing agent generally used for polyolefins and a phenolicanti-oxidant using a Henschel mixer, and the mixture was melt-kneaded at290° C. with an extruder to obtain pellets. The pellets were formed intoa 50-μm thick, 300-mm wide cast-film with a cast-film forming machineequipped with a T-die at a cylinder temperature of 310° C. and achill-roll temperature of 60° C. The properties of the film obtainedwere evaluated. The results are shown in Table 3.

Example 14

Polymerization was performed similarly to Example 13 except that 0.9 kgof 1-decene was added as a comonomer besides 84.2 kg of4-methyl-1-pentene to yield 16 kg of a polymer. The properties of thepolymer obtained were evaluated. The results are shown in Table 3.

Example 15

Polymerization was performed similarly to Example 13 except that 0.9 kgof 1-decene was added as a comonomer besides 84.2 kg of4-methyl-1-pentene and that cyclohexylmethyldimethoxysilane (CMMS) wasadded in place of 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) toyield 22.4 kg of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 3.

Example 16

Polymerization was performed similarly to Example 13, except that solidtitanium catalyst component [A-1] was changed to [A-3], 0.9 kg of1-decene was added as a comonomer besides 84.2 kg of 4-methyl-1-pentene,and cyclohexylmethyldimethoxysilane (CMMS) was added in place of2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP), to yield 24.8 kg of apolymer. The properties of the polymer obtained were evaluated. Theresults are shown in Table 4.

Example 17

Polymerization was performed similarly to Example 13, except that 3.0 kgof an equi-mass mixture of 1-hexadecene and 1-octadecene was added ascomonomers besides 84.2 kg of 4-methyl-1-pentene, the polymerizationtemperature was 33° C., and no 2-methyl-2-n-propyl-1,3-diethoxypropane(MPEP) was added, to yield 8.1 kg of a polymer. The properties of thepolymer obtained were evaluated. The results are shown in Table 4.

Example 18

Polymerization was performed similarly to Example 13, except that 3.0 kgof an equi-mass mixture of 1-hexadecene and 1-octadecene was added ascomonomers besides 84.2 kg of 4-methyl-1-pentene, and the polymerizationtemperature was 33° C., to yield 7.9 kg of a polymer. The properties ofthe polymer obtained were evaluated. The results are shown in Table 4.

Example 19

Polymerization was performed similarly to Example 13, except that 3.0 kgof an equi-mass mixture of 1-hexadecene and 1-octadecene was added ascomonomers besides 84.2 kg of 4-methyl-1-pentene, the polymerizationtemperature was 33° C., and cyclohexylmethyldimethoxysilane (CMMS) wasadded in place of 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP), toyield 10.5 kg of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 4.

Example 20

Polymerization was performed similarly to Example 13, except that solidtitanium catalyst component [A-1] was changed to [A-3], 3.0 kg of anequi-mass mixture of 1-hexadecene and 1-octadecene was added ascomonomers besides 84.2 kg of 4-methyl-1-pentene, the polymerizationtemperature was 33° C., and cyclohexylmethyldimethoxysilane (CMMS) wasadded in place of 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP), toyield 9.6 kg of a polymer. The properties of the polymer obtained wereevaluated. The results are shown in Table 4.

Comparative Example 7

Polymerization was performed similarly to Example 13, except that solidtitanium catalyst component [A-9] was used, 0.9 kg of 1-decene was addedas a comonomer besides 84.2 kg of 4-methyl-1-pentene, and no2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) was used, to yield 15.6kg of a polymer. The properties of the polymer obtained were evaluated.The results are shown in Table 3.

Comparative Example 8

Polymerization was performed similarly to Example 13, except that 0.9 kgof 1-decene was charged as a comonomer besides 84.2 kg of4-methyl-1-pentene, titanium trichloride (TAC-131, Toho Titanium) anddiethylaluminum chloride were used in place of solid titanium catalystcomponent [A-1], and no 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP)was used to yield 18.4 kg of a polymer. The properties of the polymerobtained were evaluated. The results are shown in Table 3.

Comparative Example 9

Polymerization was performed similarly to Example 13, except that solidtitanium catalyst component [A-9] was used, 3.0 kg of an equi-massmixture of 1-hexadecene and 1-octadecene was added as comonomers besides84.2 kg of 4-methyl-1-pentene, and the polymerization temperature was33° C., and no 2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) was used,to yield 5.3 kg of a polymer. The properties of the polymer obtainedwere evaluated. The results are shown in Table 4.

Comparative Example 10

Polymerization was performed similarly to Example 13, except that 3.0 kgof an equi-mass mixture of 1-hexadecene and 1-octadecene was used ascomonomers besides 84.2 kg of 4-methyl-1-pentene, titanium trichloride(TAC-131, Toho Titanium) and diethylaluminum chloride were used in placeof solid titanium catalyst component [A-1], and no2-methyl-2-n-propyl-1,3-diethoxypropane (MPEP) was used, to yield 5.8 kgof a polymer. The properties of the polymer obtained were evaluated. Theresults are shown in Table 4.

TABLE 3 Examples Comparative Examples 13 14 15 16 7 8 C₃ or higherα-olefin (1) 4-Methyl-1-pentene olefin α-olefin (2) — 1-Decene 1-Decene1-Decene 1-Decene 1-Decene Solid titanium Designation A-1 A-1 A-1 A-3A-9 TAC-131 catalyst Ether (general MPEP MPEP MPEP DEEP BPMP — component(I) formula (1)) Main Ether (general MPEP MPEP — — — — polymerizationformula (3)) Electron donor — — CMMS CMMS — — (IV) Polymer Apparent bulk440 430 440 450 430 390 (white solid) density (kg/m³) MFR (g/10 min) 5.40.43 0.27 0.44 0.82 0.72 Melting point 240.0 232.0 232.0 232.0 233.0 234(Tm)(° C.) Molecular weight 10.8 12.0 11.8 12.7 11.2 26.1 distribution(Mw/Mn) Content of 1.9 1.1 2.4 2.3 7.3 3.1 n-decane-soluble component(wt %) Content of — 3.2 3.1 3.0 3.2 3.2 structural units derived fromα-olefin (2): b₁ (wt %) Amount of polymer in filtrate (wt %) 0 0.9 0.80.1 3.7 0.7 Tacticity (t-II) (wt %) 98.1 98.4 96.8 97.6 93.8 96.2Content of structural units — 9.8 9.8 8.7 5.9 6.2 derived from α-olefin(2) in n-decane-soluble component: a₁ (wt %) Content of structural units— 6.1 6.1 5.4 3.6 3.8 derived from α-olefin (2) in n-decane-solublecomponent: d₁ (mol %) a₁/b₁ — 3.1 3.2 2.9 1.8 1.9 Mechanical Tensileelongation 2 31 28 27 30 29 Property at break (%) (Toughness) FilmBlocking factor 2.0 3.2 3.9 3.7 6.8 5.9 c₁ (g/cm) c₁/d₁ — 0.5 0.6 0.71.9 1.6

TABLE 4 Examples Comparative Examples 17 18 19 20 9 10 C₃ or higherα-olefin (1) 4-Methyl-1-pentene olefin α-olefin (2)1-Hexadecene/1-octadecene mixture Solid titanium Designation A-1 A-1 A-1A-3 A-9 TAC-131 catalyst Ether (general MPEP MPEP MPEP DEEP BPMPcomponent (I) formula (1)) Main Ether (general — MPEP — — — —polymerization formula (3)) Electron donor — — CMMS CMMS — — (IV)Polymer Apparent bulk 430 430 430 440 420 380 (white solid) density(kg/m³) MFR (g/10 min) 3.6 3.4 2.7 4.7 8.8 7.8 Melting point 227.0 228.0228.0 228.0 229.0 227 (Tm)(° C.) Molecular weight 25.4 25.3 25.5 25.110.2 27.3 distribution (Mw/Mn) Content of 14.6 12.6 12.2 14.0 18.5 10.8n-decane-soluble fraction (wt %) Content of 3.7 3.9 3.9 3.7 4.0 4.0structural units derived from α-olefin (2): b₂ (wt %) Polymer content infiltrate (wt %) 5.9 1.1 2.5 1.6 5.7 3.9 Tacticity (t-II) (wt %) 79.586.3 85.3 84.4 79.3 85.3 Content of structural units 16.0 20.4 20.4 18.510.3 10.6 derived from α-olefin (2) in n-decane-soluble component: a₂(wt %) Content of structural units 6.3 8.3 8.3 7.4 3.9 4.0 derived fromα-olefin (2) in n-decane-soluble component: d₂ (mol %) a₂/b₂ 4.3 5.2 5.25.0 2.6 2.7 Mechanical Tensile elongation 58 56 57 65 50 48 Property atbreak (%) (Toughness) Film Blocking factor 4.6 4.2 6.8 5.0 8.0 6.9 c₂(g/cm) c₂/d₂ 0.7 0.5 0.8 0.7 2.1 1.7

INDUSTRIAL APPLICABILITY

The present invention can provides a highly active polymerizationcatalyst for producing a polymer of a C₃ or higher α-olefin with moreexcellent tacticity and crystallinity, and a process for producing theα-olefin polymer, having outstanding industrial value.

The invention claimed is:
 1. A film obtained by forming a copolymer containing 80 to 99.9 mass % of structural units derived from 4-methyl-1-pentene and 0.1 to 20 mass % of structural units derived from at least one α-olefin having 3 to 11 carbon atoms except 4-methyl-1-pentene, wherein the ratio c₁/d₁ is in the range of 0.1 to 1.5, c₁ representing the blocking factor in g/cm of the film, d₁ representing the content in mol % of structural units derived from the α-olefin(s) having 3 to 11 carbon atoms except 4-methyl-1-pentene in the n-decane-soluble component of the copolymer.
 2. A release film made of the film according to claim
 1. 